A number of vascular diagnostic and interventional medical procedures are now performed translumenally. A catheter is introduced to the vascular system at a convenient access location and guided through the vascular system to a target location using established techniques. Such procedures require vascular access, which is usually established during the well-known Seldinger technique. Vascular access is generally provided through an introducer sheath, which is positioned to extend from outside the patient body, through a puncture in the femoral artery for example, and into the vascular lumen. Catheters or other medical devices are advanced into the patient's vasculature through the introducer sheath, and procedures such as balloon angioplasty, stent placement, etc. are performed.
When vascular access is no longer required, the introducer sheath is removed and bleeding at the puncture site stopped. One common approach for providing hemostasis (the cessation of bleeding) is to apply external force near and upstream from the puncture site, typically by manual or “digital” compression. This approach suffers from a number of disadvantages. It is time consuming, frequently requiring one-half hour or more of compression before hemostasis is assured. Additionally, such compression techniques rely on clot formation, which can be delayed until anticoagulants used in vascular therapy procedures (such as for heart attacks, stent deployment, non-optical PTCA results, and the like) wear off. This can take two to four hours, thereby increasing the time required before completion of the compression technique. The compression procedure is further uncomfortable for the patient and frequently requires analgesics to be tolerable. Moreover, the application of excessive pressure can at times totally occlude the underlying blood vessel, resulting in ischemia and/or thrombosis. Following manual compression, the patient typically remains recumbent from four to as much as twelve hours or more under close observation so as to assure continued hemostasis. During this time renewed bleeding may occur, resulting in blood loss through the tract, hematoma and/or pseudo-aneurysm formation, as well as arteriovenous fistula formation. These complications may require blood transfusion and/or surgical intervention.
The incidence of complications from compression induced hemostasis increases when the size of the introducer sheath grows larger, and/or when the patient is anti-coagulated. It is clear that the compression technique for arterial closure can be risky, and is expensive and onerous to the patient. Although the risk of complications can be reduced by using highly trained individuals, dedicating such personnel to this task is both expensive and inefficient. Nonetheless, as the number and efficacy of translumenally performed diagnostic and interventional vascular procedures increases, the number of patients requiring effective hemostasis for a vascular puncture continues to increase.
To overcome the problems associated with manual compression, the use of bioabsorbable fasteners or sealing bodies to stop bleeding has previously been proposed. Generally, these approaches rely on the placement of a thrombogenic and bioabsorbable material, such as collagen, at the superficial arterial wall over the puncture site.
A more effective approach for vascular closure has been proposed wherein a suture applying device is introduced through the tissue tract with a distal end of the device extending through the vascular puncture. One or more needles in the device are then used to draw suture through the blood vessel wall on opposite sides of the puncture, and the suture is secured directly over the adventitial surface of the blood vessel wall to provide highly reliable closure. One such suturing device is described in U.S. Pat. No. 6,136,010, the full disclosure of which is incorporated herein by reference.
Other examples of devices that can be used to suture or otherwise close an opening in a patient tissue are described in U.S. Pat. Nos. 5,417,699 and 5,527,322 of Klein et al.; U.S. Pat. No. 5,902,311 of Andreas et al.; U.S. Pat. No. 6,245,079 of Nobles et al.; U.S. Pat. No. 6,436,109 of Kontos; U.S. Pat. No. 5,304,184 of Hathaway et al.; U.S. Pat. No. 5,431,666 and U.S. Pat. No. 5,562,686 of Sauer et al.; U.S. Pat. No. 5,676,689 to Kensey et al.; and U.S. Pat. No. 6,391,048 to Ginn et al., the full disclosures of which are incorporated herein by reference.
While a significant improvement over the use of manual pressure, clamps, and collagen plugs, certain design criteria have been found to be important to successful suturing to achieve vascular closure. For example, it is highly beneficial to properly direct the needles through the blood vessel wall at a significant distance from the puncture so that the suture is well anchored in the tissue and can provide tight closure. It is also highly beneficial to insure that the needle deployment takes place when the device is properly positioned relative to the vessel wall.
The ease of deployment and efficacy of the procedure can further be enhanced by reducing the cross-section of that portion of the device which is inserted into the tissue tract and/or the vessel itself, which may also allow closure of the vessel in a relatively short amount of time without imposing excessive injury to the tissue tract or vessel. In some cases, however, a larger size device may be appropriately used when the puncture is larger, as in the case of percutaneous repair of an aortic aneurysm using a stent graft (also referred to as abdominal aortic aneurysm (AAA) repair). Readily available suturing devices, which are smaller in size, are typically not desirable for closing such larger sized vessel punctures because the shaft or sheath diameter of such suturing devices are too small to provide hemostasis or adequate tissue capture during the closure procedure. Also, in such procedures, it may be desirable to close the puncture with more than one suture loop, in which case adapters may be provided on suturing devices that help position each loop of suture in a desired position relative to the puncture, as well as provide hemostasis. Such adapters may be used in lieu of provided larger size suturing devices.
For the above reasons, it would be desirable to provide improved devices, systems, and methods for suturing vascular punctures. It would be particularly beneficial if these improved devices provided some or all of the benefits while overcoming one or more of the disadvantages discussed above.